The proposed measurement method they reported, referred to as the scanning radiometer method, utilized a relatively inexpensive off-the-shelf net radiometer to make the measurements.
This method was found applicable for radiant heat gain measurements; however, an infrared imaging technique requires expertise and is much more difficult to use, and the equipment is much more expensive than the net radiometer.
The radiant heat loss from equipment was measured using a Fritschen--type net radiometer mounted on a scanning arm.
During the measurements in 2002, a net radiometer (NR Lite, Kipp & Zonen, Netherlands) was installed 4.0 m above the ground, to measure net radiation of the coffee crop.
(1975) and Thorpe (1978) used eight fixed linear net radiometers deployed along a row in an apple orchard, in order to integrate all-wave radiation absorbed by 1.0 m of hedgerow, assuming horizontal cylindrical geometry of measurements.
The number of eight net radiometers was the same used by Landsberg et al.
(1998) show that the radiant heat gain from equipment can be measured by scanning the entire hemisphere around the equipment with a net radiometer. After scanning the hemisphere, the total radiant heat gain can then be determined by summing the product of the radiant fluxes and their associated area over the hemisphere.
To measure net shortwave and longwave radiant heat gains from the luminaires to the conditioned space, a net radiometer is used.